Transmission operating mechanism



March 18, 1952 Filed June 26, 1948 T. H. THOMAS Er'AL Zi Hulk TRANSMISSION OPERATING MECHANISM 3 Sheets-Sheet l JNVENTORS THOMAS/K THO/V lCf T. H. THOMAS ETAL ,643 TRANSMISSION OPERATING MECHANISM March 18, 1952 Filed June 26, 1948 a Sheeis-Sheat 2 IIH I I 66 d0 40' ii 54 30 d9 1 1g 5 /2 a5. .93 n 92 a5 95 March 18, 1952 THOMAS ETAL 2,589,643

TRANSMISSION OPERATING MECHANISM Filed June 26, 1948 3 Sheets-Sheet 3 lllk l l k INVENTOR5 mama/x 77/0/745 MR1 /R-P/?/C BY Ava-#44 0 m 104/ wa e -a/ Patented Mar. 18, 1952 TRAN SMIS SION OPERATING MECHANISM Thomas H. Thomas, Earl R. Price, and Richard H. Long, South Bend, Ind., assignors to Bendix Aviation Corporation, South Bend, Ind, a corporation of Delaware Application June 26, 1948, Serial N 0. 35,426

1 Claim.

This invention relates to motor vehicles and more particularly to controlling means for power transmission systems thereof.

More specifically, the invention relates to gear shifting mechanism and is of particular utility when employed in connection with speed changing and direction reversing gearing commonly used in coupling internal combustion engines of automobiles with the driving vehicle wheels or other propelling devices.

One object of the invention is to provide power operated means for operating a two-speed transmission mechanism, preferably mounted on the differential housing of an automotive vehicle or mounted within said housing and constituting a part of the differential and rear axle construction. Such a mechanism serves to supplyment the conventional change speed transmission by providing, in addition to the conventional three-speeds forward and reverse driving ratios, two additional driving ratios between the power plant and the rear wheels. Thus for each of the two settings of the supplemental transmission there are provided, by the standard transmission, four different'gear ratios, making eight different ratios in all.

Such a mechanism provides a more eflicient power plant, both in climbing hills and on level ground, there being a quiet performance of the motor at high vehicle speeds, and accordingly less wear and tear on the motor parts. On the boulevard or in the country with the car moving at say twenty to sixty miles per hour the two-speed transmission may be operated to select its high ratio; thereupon the car continues at the same speed and the motor speed drops say one-third of its former speed. There is thus provided a mechanism that insures a minimum of noise and vibration, saves wear and tear on moving parts, and in general prolongs the life not only of the motor but of the entire automobile.

According to one desirable construction there is provided a double acting electric motor adapted to be operably connected to the two-speed axle mechanism of heavy duty vehicles, said motor being controlled by a manually operable mechanism preferably mounted in the dashboard of the vehicle.

A further object of our invention is to provide a simple, compact and easily serviced double acting motor unit adapted to operate a change speed transmission mechanism of,an automotive vehicle said unit including electrical power means, preferably a plurality of solenoids, and further including yieldable force transmitting means serving to interconnect the power means with the transmission to be operated; and a further object of our invention is to provide a locking mechanism, cooperating with electrical power means and yieldable means of a transmission operating mechanism, and operative to insure an operation of the mechanism until the transmission is established in gear.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawings wherein three embodiments of the invention are illustrated by way of example.

Figure l is a diagrammatic view of one embodiment of the transmission operating mechanism constituting our invention;

Figure 2 is a sectional View disclosing details of the electric motor unit of the mechanism of Figure 1;

Figure 3 is a diagrammatic view of another embodiment of the transmission operating mechanism constituting our invention;

Figure 4 is a sectional view disclosing details of the electric motor unit of the mechanism of stituting our invention is preferably employed to operate a two-speed axle transmission mechanism of an automotive vehicle. Referring to Figures 1 and 2 disclosing one embodiment of our invention a transmission operating power unit 10 is mounted on a casing of a two-speed axle transmission mechanism l2. As disclosed in Figure 2 this transmission mechanism includes low speed gears l4 and I6 and high speed gears I 8 and 20, one or the other of said pairs of gears being drivably interconnected with each other by an axially shiftable collar 22 actuated by a shifter fork 24. A spring loaded poppet member 25 may also be included in the transmission mechanism said member contacting the collar 22 and serving to aid the shifter fork 24 in holding the collar in its several operative positions. The gears I B and I8 preferably include a common body portion and the gear setting of the transmission is established by moving the collar 22 to the right or left, Figure 2 to interconnect the gear members. The shifter fork 24 is connected to a shift rail 25 which is slidably mounted within a casing portion 28 of the power unit Id.

The shift rail 26 is provided with a hollow p-rojection 30 which houses a push rod 32 connected to the two part armature 3 5 of a solenoid motor 36 constituting the power means of the unit Hi. The motor 36 includes a grounded hold-in coil 38 of relatively light wire and a pull-in coil 60 of relatively heavy wire the latter being connected to the movable contact 42 of a breaker switch 44. A fixed contact 43 of the latter switch is grounded as disclosed in Figure 2. The movable contact M is preferably pivotally mounted at 48 to a casing 53 of the motor 33; and a return spring 52 serves to bias the contact 32 into switch 44.

A flange 54 fixedly connected to the armature I 34 moves into engagement with the movable contact 42 to open the switch 44 when the motor 36 is energized by the passage of current through the coil for with this operation the armature 34 moves to the left, Figure 2, to establish the transmission in its low gear setting. At this time current is passed through the hold-in coil 38 thereby acting to hold the armature 34 in its low gear position after the pull-in coil 30 is deenergized by the opening of the switch ed. A compression spring 56, interposed between an end wall 51 of the casing Fall and a flange 53 fixed to the armature 33, serves to move the push rod 32 to the right to establish the transmission E2 in its high gear setting after the hold-in coil 38 is de-energized. The flange 53, which is preferablyan' electrical conductor and connected to the armature 34 by insulation material, not shown, serves as an electrical conductor interconnecting the coils 38 and 40.

Describing the remainder of the electrical means for controlling the coils 38 and so, a conductor 59, Figure 1, interconnects said coils with a relay 6| including a normally opened switch 63 and a grounded winding 65. As is disclosed in Figure 1 the winding 65 is electrically connected by a conductor 61, with a manually operated selector breaker switch 59 preferably mounted in the dashboard of the vehicle; and the relay switch 63 is electrically connected, by a conductor H, to a grounded battery 13. The switch 69'is' of course also electrically connected to the battery 13. The switch 39 is actuated by a manually operated handle 15- which may be rotated clockwisevto close the switch and counterclockwise to open said switch. When the switch 69 is closed the switch 33 is closed to effect an energization of the motor 36 thereby establishing the transmission l2 in its low gear setting; and when the switch 39 is opened the switch 33 is opened to de-energize the motor 36 thereby permitting the spring to expand to establish the transmission l2 in its high gear setting.

Completing the description of the force transmitting means interconnecting the power unit H] and the transmission, a shifter spring 30 sleeved over the push rod 32 abuts, at its ends, washers 62 and 54 also sleeved over said rod; and a spacer collar 66 sleeved within the projection 33 serves to limit the compression of the spring 53. This spring is preferably of such strength as to be compressed by a force which is less than the force exerted by either the spring 53 or the solenoid motor 36 when energized; and it is also'to benoted that the spring 60, together with the parts cooperating therewith, provide a double acting yieldable force transmitting means interconnecting the transmission with the motor.

As to the remainder of the power plant of the vehicle disclosed in Figure 1 this mechanism includes a step type of change speed transmission '39, preferably a three speeds forward and reverse transmission; and said power plant also includes internal combustion engine '15 controlled in large measure by the operation of an accelerator ll.

Describing now the operation of the shifter mechanism disclosed in Figures 1 and 2 it will be assumed that'the vehicle is at a standstill with the engine idling and that the switch 69 is closed to establish the transmission l2 in its low gear position. The motor 36 is then energized the armature 34 moving to the left to compress the spring 69 and move the collar 22 to interconnect the gears 3 and l 6, all as is disclosed in Figure 2. The driver will then depress the accelerator l! to get the vehicle under way; and when the desired speed is reached, with say the high speed setting of the transmission 73, then the driver will open the switch 69 andrelease the accelerator to effect the high gear operation of the power unit IE9.

Describing this operation of the unit ie when the switch 69 is opened motor 35 is de-energized thereby permitting spring 56 to expand to move the rod 32 to the right, Figure 2. By this operation the washer 32 acts to compress the spring 53, the collar 22 remaining in its low gear position so long as the engine is operating to impose a driving load upon said collar and the in terconnected gears Hi and it; then when the driver releases the accelerator to appreciably reduce the torque load upon the collar 22 the spring 60 expands to neutralize the transmission I2. A subsequent synchronization of the high speed gears l8 and 20 results in a movement of the collar 22 to the right, Figure 2, to effect the high gear setting of the transmission. The operation of the transmission is therefore effected in three stages. It is also to be noted that with this high gear operation of the transmission operating motor unit I!) the switch 44 is closed in preparation for a subsequent low gear operation of the said unit.

To subsequently effect a low gear operation of the transmission the driver will close the switch 59 thereby energizing th motor 36. Describing this operation the passage of current through the coil 40 serves to move the armature 34 to the left, Figure 2, the first increment of said movement having no effect on the switch 43; ho-W- ever, after the armature 34 has moved a rela- 1 tively short distance the stop 54 contacts the contact 42 to open said switch. In this operation the coil 33 remains energized to maintain a load on the rod 32. As'to the three stage operation of the yieldable force transmitting means interconnecting the armature 34 and the collar 22, this operation is the same as that described above in establishing the transmission in its high operating power means constituting 'my invention. "In this mechanism the two-speed transmission'to be operated is a duplicate of'the transmission 12 of Figure 1 and is in'dicatedby the reference numeral I2; and the yieldable iorce transmitting means interconnecting the transmission 12' with the transmission operating power means also duplicates the corresponding mechanism of Figure 2. This force transmitting means in Figure 4 is indicated by the reference numeral 1'82. The transmission operating power means of Figures 3 and 4 is indicated as a whole by the reference numeral It said power means constituting a power unit similar in operation to the power unit I of Figures 1 and 2.

The motor portion of the unit I0 includes two separate electrical solenoid motors Maud 85, the motor 84 including a hold-in coil '83 and a pull-in coil 85, and the motor 88 including a hold-in coil 81 and a pull-in coil 08. The motor 85 includes an armature 89 which is extended to provide armature -90 for the -motor 34. it follows that the armatures 89 and '90 together constitute a two part armature for the motor portion of the unit II). A collar QI fixedly secured to the armature 90 moves into contact with the movable contact 02t0 separate the same from a fixed contact 93 of a breaker switch 95; and a collar fixedly secured to the armature 89, is adapted to separate amovahl contact '95 of a breaker switch 9! from a fixed contact Q8 of said switch. The movable contacts of the switches 95 and 0? are biased into contact with the fixed contacts of said switches by the return springs disclosed in Figure 4. The pull-in coils of both switches are connected to the movable contacts of the switches; and the hold-in coils and fixed con tacts of the said switches are grounded, all as is disclosed in Figure 4.

Describing now the electrical means for controlling the electric motors 84 and 86 there is provided a relay I80 comprising a normally closed. switch M4 and winding Hit. The pull-in and hold-in coils of motor i=4 are electrically connected to the relay switch IN. The pull-in and hold-in coils of switch 35 are electrically connected to a relay switch I02; and the switches I02 and I04 and the relay winding I06 are electrically connected to a grounded battery I08, all as is disclosed in Figure 3. The relay winding I06 is also wired to a grounded selector switch IIO which may be conveniently mounted in the dash of the vehicle.

Describing the operation of the motor unit I0 it will be assumed that the vehicle is at a standstill with the engine idling, and that the selector switch H0 is open. The relay switches I02 and I04 will then be opened and closed respectively, all as is disclosed in Figure 3; and with this setting of the controls the motor 8% is energized to move the armatures 90 and 83 to the left to the position disclosed in Figure l.

. The switches and 01 are thus opened and closed respectively, and the transmission 52 is established in its low gear setting; and with this operation the hold-in coil 83 of the motor 84 will be operative to maintain the low gear setting of the parts of the mechanism.

The driver will then depress the accelerator to get the vehicle under way and after the desired Vehicle speed is reached he will effect the high gear setting of the transmission I 2' by closing the selector switch IIO. This operation will energize the relay I00 to close the switch I02 and open the switch I04 thereby effecting 6 an energization-of the motor 86 and a deenergization of the motor 84. The armature 89 will then be moved to the right, Figure 4, to establish the transmission I2 in its high gear setting the switch 9'! being broken after said armature has moved a relatively short distance; however, the hold-in coil 8'! remains energized to maintain the parts of the mechanism in'their high gear positions. As with the mechanism of Figures 1 and 2 the operation of the accelerator to control the driving torque cooperates with the motor unit I0 in o crating the mechanism I 2'.

In describing the mechanism of Figures 3 and 4 the opera ions of the yieldable force transmitting connection 82 and the transmission I2 were not described inasmuch as said operations were included in the description of the mechanism of Figures 1 and 2.

There is thus provided,'by the transmission operating mechanism of Figures 3 and 4, a simple and compact double acting three-stage power unit It) for operating the two speed transmission I2. The combined efect of the pull-in and hold-in coils of the electric motors 84 and 86 serve to sufficiently load the force transmitting mechanism 82 to effect the desired operation of the transmission, the hoid-in coils operating to insure a completion of said operation once initiated.

There is disclosed in Figures 5 and 6 yet another embodiment of our invention; and the two speed transmission and force transmitting yieldahle connection of said embodiment duplicate in construction an operation the corresponding mechanisms of the embodiments disclosed in Figures 1 to 4 inclusive. The yieldable force transmitting connection of Figure 6 is indicated by the reference numeral 82, and the transmission mechanism of this figure is indicated by the reference numeral I2.

With the mechanism of Figure 6 a reversable electdc motor II 2 is operably connected with the force transmitting connection 82 by a crank IIll the motor and connection together going to make up a transmission operating power unit generally similar in operation to the above described power units I i; and I0. The electrical means for controlling the motor II 2 is disclosed in Figure 5 and includes a double pole, double throw switch Ht which may be conveniently mounted on the dash of the vehicle. When a movable contact member I E8 of the latter switch is rotated in a clockwise direction an electrical circuit is completed through the motor IIZ to eiTect say, the high gear setting of the transmission; and when the contact member H8 is rotated in a counterclockwise direction a circuit through the motor is completed to effect the low gear operation of the transmission. One or the other of breaker switches I29 and I22 are preferably opened by the crank H4 when the power element of the motor II2 has completed its operation of the cooking the spring of the force transmitting connection 82 that is when said power element has moved a certain distance; and a Geneva Loc mechanism built into said motor serves to hold the crank in one or the other of its operative positions that is the positions assumed when the aforementioned spring is cooked. This holding mechanism prevents a reversal, that is hunting movement of the crank H t under the load of the cocked spring at the time the gears of the transmission are being synchronized.

There is thus provided, by the transmission operating power means of our invention, a simple, compact and easily serviced mechanism for operating a two-speed transmission of an automotive vehicle. The motor portion of the power means of our invention is easily controlled by a dash mounted switch and said motor serves to compress the yieldable means of a force transmitting means to subsequently efiect a meshing of the gears of the transmission; and this meshing operation is relatively quiet in view of the relatively low strength of said yieldable means. With the mechanism of our invention the yieldable force transmitting means and the motor means are combined to form a compact two part unit one part of the unit constituting a motor and the other part a yieldable force transmitting means adapted to interconnect the motor with the transmission.

Although only three embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

We claim:

Power means for actuating the shifting fork of a transmission including a transmission operating power unit comprising an electric and spring operated motor having a casing, a partition dividing the easing into two compartments, a plurality of coils within one of the compartments, one of said coils serving as pullin coil and the other of said coils serving as a hold-in coil, a reciprocable armature actuated by said coils, two spaced apart flange members fixedly mounted on the armature, a motor operating' spring member interposed between one end of the latter compartment and one of the flanges, and a grounded motor controlling breaker switch mechanism actuated by one of the flanges and mounted within the latter compartment, said breaker switch being electrically connected to one of said coils, said power unit furtherincluding a double acting force transmitting means mounted within the other of the aforementioned compartments and adapted to interconnect the armature and shifting fork.

THOMAS H. THOMAS. EARL R. PRICE. RICHARD H. LONG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,373,099 Ross Mar. 29, 1921 1,720,989 Ahlm July 16, 1929 2,062,104 Prince Nov. 24, 1936 2,220,813 Derungs Nov. 5, 1940 2,231,876 Beltz Feb. 18, 1941 2,241,631 Claytor May 13, 1941 2,257,838 Claytor Oct. 7, 1941 2,266,598 Hale Dec. 16, 1941 2,267,603 Claytor Dec. 23, 1941 2,310,878 Stephan Feb. 9, 1943 2,373,259 Price Apr. 10, 1945 2,402,343 Price June 18, 1946 2,444,953 Polomski July 13, 1948 2,462,779 Russell Feb. 22, 1949 

